1. Field of the Invention
This invention relates to the construction and repair of bridge decks, roads and sidewalls. In particular, this invention provides an integral, preformed module which can be constructed in a factory under ideal conditions and transported to a construction site to construct or repair a bridge deck, roadway, sidewalk or similar area on which is desired a hard wear surface.
2. Background Art
It is well-known to use modular, precast concrete slabs to construct roadways, sidewalks, bridge decks and similar surfaces. An example of such precast concrete paving slabs which may be set upon a roadway subsurface is disclosed in U.S. Pat. No. 1,984,944. It is also known to reinforce concrete roadways, whether constructed in modular form or as a continuous casting at the job site, with metal or plastic grids, as is disclosed in U.S. Pat. No. 2,184,146 and 4,168,924. These grids, however, are used solely for reinforcement and not as a base for a pavement module. It is also known to use a polyethylene or paper sheet over a base layer of resilient hydrophobic particles to prevent displacement of the particles and to prevent curing of the concrete to the particles, as is disclosed in U.S. Pat. No. 3,545,348.
The prior art precast, modular concrete panels in which a grating or grid is used allow the concrete to fill the interstices of the grating or grid. This results in an extremely heavy modular panel which is unwieldy and costly to transport to construction sites and imposes undesirable dead load which serves no useful purpose in bridge deck construction. Open grating bridge decks without a concrete or similar wear surface are unacceptable because they are too dangerous to traffic.
The invention claimed and described herein uses an impervious intermediate layer to prevent the concrete wear surface from filling the interstices of the base grating. The weight of the panel is approximately 40% of the prior art designs. The intermediate sheet also provides an effective barrier and coating for the grating or grid base support member to protect it from the elements and premature deterioration.